Eaton EEV-7202, Руководство по обслуживанию, Страница: 13 / 63

13
Disassembly precautions and inspection of expendable parts
It is assumed in the detailed disassembly instructions that the lubricant has been drained
and the necessary linkage and air lines have been removed from the chassis. Follow each procedure
closely in each section, making use of both the text and the pictures.
Cleanliness - Provide a clean place to work. It is important that no dirt or foreign material enters the unit
during repairs. The outside of the unit should be carefully cleaned before starting the disassembly. Dirt
is abrasive and can damage bearings.
1.
Assemblies -
When disassembling the various assemblies, such as the mainshaft, range change
epicyclic and layshaft, place all parts on a clean bench in the same sequence as removed. This
procedure will simplify Assembly and reduce the possibility of losing parts. When pulling off
synchronizer hubs follow the procedures detailed in 'Disassembly’ using a suitable press of adequate
capacity. Failure to adhere to the recommended procedures may cause irreparable damage.
2.
Snap rings - Remove snap rings with pliers designed for this purpose. New selective fit snap rings
must be fitted as specified in ''Assembly”.
3.
Bearings - Carefully wash and re-lubricate all bearings as removed and protectively wrap until ready
for use. Remove bearings with pullers designed for this purpose.
4.
When pressing - Apply force to shafts, housings etc. with restraint. Movement of some parts is
restricted. Do not apply force after the part being driven stops solidly. Use soft hammers for all
disassembly work. Do not use pry bars or chisels to separate casing halves and housings or irreparable
damage may be caused.
Before assembling the transmission, the individual parts should be carefully checked and any that are
damaged should be rejected. These should be renewed. This inspection procedure should be carefully
followed to ensure the maximum wear life from the rebuilt unit. The cost of a new part is generally a
small fraction of the total cost of downtime and labour. The use of a questionable part may make
additional repairs necessary before the next regularly scheduled overhaul. Recommended inspection
procedures are set forth in the following check list:
A. Bearings
1. Wash all bearings in clean solvent. Check rollers and races for pits and spalled areas. Renew
damaged bearings.
2. Lubricate undamaged bearings and check for axial and radial clearances. Renew bearings with
excessive clearances.
3. Check fits of bearings in housing bores. If outer races turn too freely in the bores, the housing should
be renewed. Check housing bores for signs of wear prior to taking this action. Renew housing if
wear is seen as a result of bearing spin (see Item L).
4. Planet gear bearings consist of two tracks of 18 loose assembled rollers, i.e. 36 rollers per gear,
separated by a spacer. If any rollers in a gear set are worn or damaged the whole set must be
renewed.